The long-term objective of this grant is to understand at a molecular level the structure, function, and regulation of the thiazide diuretic- sensitive Na+:Cl- cotransporter present in the mammalian kidney. the specific objectives of this grant proposal are: (i) to clone the thiazide-sensitive Na+:Cl- cotransporter from rat kidney using a nucleotide probe generated from the cDNA encoding the thiazide-sensitive Na+:Cl- cotransporter that we have recently cloned from the urinary bladder of the winter flounder, Pseudopleuronectes americanus; (ii) to determine the nucleotide and amino acid sequences of the rat renal thiazide-sensitive cotransporter, to develop a topology model the cotransporter, and to compare the nucleotide and amino acid sequences of the Na+:Cl- cotransporter with other sequenced proteins, especially other cotransporter proteins; (iii) to assess the functional characteristics of the cotransporter as expressed in Xenopus laevis oocytes and to compare these characteristics with those of the flounder bladder transporter; (iv) to prepare polyclonal antibodies against the cotransporter which will be used to assess expression of the cotransporter protein; (v) to determine the distribution of the rat Na+:Cl- cotransporter mRNA and protein in both renal and non renal tissues by Northern and Western analyses, PCR of single renal tubules, and immunofluorescence; (vi) to assess whether isoforms of the thiazide- sensitive cotransporter exist in the rat kidney [esp. in the distal tubule and collecting duct] using PCR, and if isoforms can be identified, to determine the structure of these isoforms and to assess their functional characteristics. The results of these proposed studies will provide basic information on which we can begin to model [and the molecular probes on which to assess] the function and regulation of this important renal ion transporting protein at a molecular level.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
7R01DK045792-06
Application #
2502307
Study Section
General Medicine B Study Section (GMB)
Project Start
1993-01-01
Project End
1998-12-31
Budget Start
1997-04-01
Budget End
1998-12-31
Support Year
6
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Hebert, S C (1998) Roles of Na-K-2Cl and Na-Cl cotransporters and ROMK potassium channels in urinary concentrating mechanism. Am J Physiol 275:F325-7
Verlander, J W; Tran, T M; Zhang, L et al. (1998) Estradiol enhances thiazide-sensitive NaCl cotransporter density in the apical plasma membrane of the distal convoluted tubule in ovariectomized rats. J Clin Invest 101:1661-9
Mount, D B; Delpire, E; Gamba, G et al. (1998) The electroneutral cation-chloride cotransporters. J Exp Biol 201:2091-102
Remington, M C; Tarle, S A; Simon, B et al. (1997) ZBP-89, a Kruppel-type zinc finger protein, inhibits cell proliferation. Biochem Biophys Res Commun 237:230-4
Mount, D B; Hoover, R S; Hebert, S C (1997) The molecular physiology of electroneutral cation-chloride cotransport. J Membr Biol 158:177-86
Pollak, M R; Delaney, V B; Graham, R M et al. (1996) Gitelman's syndrome (Bartter's variant) maps to the thiazide-sensitive cotransporter gene locus on chromosome 16q13 in a large kindred. J Am Soc Nephrol 7:2244-8
Plotkin, M D; Kaplan, M R; Verlander, J W et al. (1996) Localization of the thiazide sensitive Na-Cl cotransporter, rTSC1 in the rat kidney. Kidney Int 50:174-83
Kaplan, M R; Plotkin, M D; Lee, W S et al. (1996) Apical localization of the Na-K-Cl cotransporter, rBSC1, on rat thick ascending limbs. Kidney Int 49:40-7
Kaplan, M R; Mount, D B; Delpire, E (1996) Molecular mechanisms of NaCl cotransport. Annu Rev Physiol 58:649-68